Coal mines were the central force of the industrial revolution. They provided a cheap source of energy for new machinery, such as steam engines. But by advancing the revolution, they have also triggered an increase in greenhouse gas emissions – and we are seeing the consequences with climate change.
Coal is now endangered in much of the developed world, replaced by cleaner energy. But what if the old coal mines could be turned into a carbon-free energy source?
A bottling company located above an old coal basin proves that it is possible. They tap into the great heat source of mine water in the labyrinth of tunnels beneath their storehouses.
“What’s exciting about this technology is that heating is one of the hardest things to decarbonize and here we are with these mines right where we need them.”
How it started: When Adam Black had to supply heat to one of Britain’s biggest bottling companies, he wanted to do it right.
As director of energy projects at Lanchester Wines, Black knew his warehouses were located directly above four layers of wells that stretch for 200 meters, flooded with mine water – possibly the power source. UK’s most underused.
“What’s exciting about this technology is that heating is one of the hardest things to decarbonize and here we are with these mines right where we need them,” Black told Geographical.
How it works: With the right tools, Mine water – heated by geothermal energy deep underground – can be used to directly heat buildings above ground.
Black brought in a few geothermal experts from Iceland (where abundant volcanoes provide two-thirds of the island’s energy), and the team drilled a hole in the mines below. The water they pumped to the surface had a nice temperature of 59 degrees Fahrenheit, reports BBC Future Planet.
59F may not seem like much, but combined with an electric heat pump it is capable of keeping acres of wine bottles at the proper temperature.
An open-loop heat pump lifts 39 liters of mine water to the surface every second. Hot water enters a heat exchanger, where the heat is concentrated into liquid ammonia at 122 degrees Fahrenheit. This heat is then transferred to the plant’s heating system, which heats the water circulating in the radiator pipes throughout the installation. The water from the mine is returned to the underground mines, where it heats up again to continue the cycle.
Geothermal heat from mines is used to meet all warehouse requirements, including keeping millions of wine bottles at the right temperature, as well as heating a nearby distribution center, reports the Financial Times .
“The wonderful irony here is that we used coal to carbonize the economy. Now we are going to use the existing coal mines to decarbonize. “
This project started almost a decade ago. Since then, the Gateshead site at Lanchester Wines has grown into the UK’s largest commercial mine water heating system.
Why this is important: Most of the UK’s largest cities outside of London are built on old coalfields. Nine million buildings, almost a quarter of all homes in the UK, sit above this untapped energy source. The British coal industry, booming for more than a century, closed its last deep mine in 2015.
Lisa Pinney, chief executive of the Coal Authority, told the Financial Times that mine water “could be a real contribution to zero carbon.”
“Abandoned mines are a large-scale opportunity to decarbonize heat,” she said.
The British Geological Survey is studying how to increase the use of heat from mine water from old industrial sites.
“The wonderful irony here is that we have used coal to carbonize the economy,” Mike Stephenson, chief scientist of the British Geological Survey, told the Financial Times. “Now we are going to use the existing coal mines to decarbonize. “
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